In the lumber industry, logs are cut into boards at saw mills. Commercial saw mill plants are typically large, complex installations operations with large sawing fixtures and machines, often including log and board conveyor mechanisms. Such commercial saw mills are capable of cutting up to and exceed one million board feet in a single day. In contrast to such large mill plants, portable saw mills satisfy a different market. Portable saw mills are smaller scale saw mills that may be moved to locations near the source of the logs. In addition, portable saw mills allow for hobbyists and craftsman to generate their own cut lumber.
In general, portable saw mills include a saw head, a carriage, and a bed. In use, a log is disposed on the bed lengthwise. An operator then moves the saw head, using the carriage, along the length of the log. The saw head itself includes a continuous band saw blade wound around two rotating band wheels. The saw head also includes a saw head housing enclosing rotating band wheels and non-cutting sections of the saw blade. The portion of the blade that engages the timber is external to the saw head housing. The saw head is affixed to the carriage, thereby allowing for relative movement of the blade with respect to the timber to be cut. The saw head also includes a gasoline-powered engine or some other prime mover of the blade.
A typical portable saw mill bed includes two elongated, parallel rails having a plurality of cross-braces known as bunks. The lumber to be cut is supported on the bunks. To this end, the bed includes further features, such as posts that provide lateral support to the log. The lateral support posts are positioned at a height that allows the saw head to safely pass over without interference. In order to facilitate cuts at different heights, the lateral support posts are typically vertically adjustable. Such lateral support posts, however, often included complex hydraulic members or other relatively complex structures to facilitate the support and vertical adjustment.
In addition, it is known to include height adjusting elements that assist in leveling logs. Such structures can also be complex adjustment structures. The complex structures add cost and inconvenience to the user.
There is a need, therefore, for bed structures for use in a saw mill such as a portable saw mill that have reduced complexity and costs.